## Core Concept
The question assesses the developmental milestones expected in a 4-year-old child, focusing on their physical and cognitive abilities. Developmental milestones are critical indicators of a child's growth and potential for reaching future developmental goals. They encompass various areas, including gross and fine motor skills.

## Why the Correct Answer is Right
At 4 years old, children are expected to have achieved certain levels of physical and cognitive development. They should be able to perform tasks that require a certain degree of coordination, balance, and cognitive understanding. For instance, most 4-year-olds can draw simple shapes, use scissors to cut straight lines, and demonstrate an understanding of basic numbers and counting.

## Why Each Wrong Option is Incorrect
- **Option A:** Drawing a square is a skill that might be challenging but can be expected in children around the age of 4 to 5 years as their fine motor skills improve.
- **Option B:** Counting 5 blocks is within the cognitive abilities of a 4-year-old, as they start to understand basic numeracy.
- **Option C:** Telling a story is also within the realm of cognitive and language skills expected at this age, as children begin to develop their narrative skills.
- **Option D:** Drawing a triangle is more complex and typically expected in children a bit older than 4, around 5 to 6 years old, as it requires more refined fine motor skills and cognitive understanding of shapes.

## Clinical Pearl / High-Yield Fact
A key developmental milestone for a 4-year-old is being able to draw a square, count up to at least 10, and start to show an understanding of basic time concepts. However, drawing complex shapes like a triangle often requires more refined motor skills, typically developed a bit later.

## Correct Answer: D. Drawing a triangle.